Based on the board game of the same name, players play against each other or AI opponents for "world conquest."
This is done by players each receiving an "empire", a major civilization during a time in history. Each player attempts to expand his civilization to gain maximum points for his turn. The next "turn" represents a new age, and the players are dealt new civilizations.
The player's goal is to extend his previous total control over the board each turn, taking control from players in previous turns, but trying to protect his own progress.